After the repeated losses at the hands of ZAFT, the Earth Alliance space force tried desperately to reverse ZAFT’s offensive momentum, they decided to launch a deep strike on the PLANT homeland. In April C.E.70, Alliance 5th and 6th fleets launched from Ptolemaeus base on the Moon and headed toward Lagrange Point 5.

On April 17, C.E.70, the incoming Alliance fleets were intercepted by ZAFT forces stationed at Jachin Due resource satellite. The battle that ensued resulted in the defeat of the Earth Alliance’s 5th and 6th fleets.

After ZAFT’s victory at Jachin Due, the PLANT Supreme Council decided to convert the resource asteroid into a military space fortress.